This section provides background information related to the present disclosure which is not necessarily prior art.
A surgical instrument may include a motor housing with a grip, an attachment, and a surgical tool. The attachment and the surgical tool may be replaced with other attachments and surgical tools. The attachment may connect to the motor housing and engage with a motor in the motor housing. The surgical tool may include a shaft and a surgical bur. The shaft extends from the surgical bur, engages with the attachment and is axially rotated by the motor.
Surgical burs are used to dissect, cut and/or shape bone during a surgical procedure. Surgical burs have various characteristics that can often conflict with each other. Some of these characteristics include cutting efficiency, stability, working length, and visibility. Improving one of these characteristics can negatively affect one or more of the other characteristics. As an example, when an enhancement is provided in an axial region (or at a tip of the surgical bur) or in a radial region (or at an equator of a surgical bur), cutting performance in other regions of the surgical bur can be negatively affected.
A length of a shaft of a surgical tool affects a working length of the surgical instrument. The working length refers to a length of the surgical instrument from a grip (or motor housing) to a cutting portion of a corresponding surgical bur. The working length includes an attachment length and an exposed length. The attachment length refers to a length of a corresponding attachment. The attachment is a portion of a surgical instrument extending from a motor (or main) housing to an exposed portion of a shaft of a surgical tool. The exposure length refers to a length of a surgical tool that is exposed subsequent to being engaged with an attachment of a surgical instrument. The exposure length is a length of a portion of the surgical tool extending from a distal end of the attachment. A distal end of a surgical bur can come in contact with tissue of a patient. The term “distal” means furthest away from a medical practitioner holding a surgical instrument with a surgical bur. The term “proximal” means towards the medical practitioner and away from the patient.
A surgeon may desire increased exposure without changing a length of a surgical tool (or working length). This may be provided by using a surgical tool with a shorter attachment and/or providing a variable exposure attachment. A variable exposure attachment allows a surgeon to change an amount of a shaft of a surgical tool that extends from the variable exposure attachment. Increasing the exposure tends to increase instability of the surgical tool. The longer the shaft of the surgical bur that extends away from the attachment, the more unstable the surgical bur can be during axial rotation of the surgical bur.